Research On The Performance And Optimization Of The Bearing Connection Mechanism Between Cab And Bottom Frame Of Mining Dump Truck

In recent years,with the rapid development of economy in our country,the development and use of natural resources is more rationalized and standardized.As a kind of special vehicle of mining machinery,the development trend of large mining dump truck in recent years is more biased to the intelligent operation system and large load capacity.As a driver’s safety protection mechanism,the cab is very important for the man-machine safety of mining dump truck.Through literature analysis,it can be seen that researches on cab safety based on the ROPS&FOPS standard are mostly limited to the cab body mechanism,while the safety protection structure experiment of mining dump truck requires not only the cab body,but also the bottom frame.The performance of the bearing connection mechanism between the cab and the chassis cannot be ignored,and it also assumes a certain structural bearing and energy absorption role.Therefore,the research on the force analysis of the bearing connection mechanism between the cab and the chassis can evaluate the influence degree of the cab base on the lateral and longitudinal loading of its ROPS,and then optimize the structural parts in the bearing connection mechanism.Improve the product design rationality of mining dump truck.In this paper,combined with the rolover protection structure of 200 t large mining dump truck,the high-strength bolt connection mechanism and welding mechanism of the cab bearing connection part were analyzed,and the selection optimization of the bolt connection mechanism,as well as the mechanical coupling performance of the bolt connection mechanism and welding mechanism were analyzed.The main contents are as follows:1.Introduce the technology and application status of mining dump truck,and summarize the main research directions and related research theories of mining dump truck ROPS&FOPS protection structure and simulation analysis at home and abroad;It can be concluded that most researches on mining dump truck structure at the present stage are focused on the body model of protection structure or the optimization of dump truck frame,and there are few researches on the bearing connection mechanism between cab and bottom frame,and the bearing connection mechanism between cab and bottom frame is mainly fixed through high-strength bolt and welding connection.Therefore,this paper focuses on the mechanical properties of high-strength bolts of200 t mining dump truck under ROPS loading conditions.2.Analysis based on the rolover protection structure standard of 200 t mining dump truck;this paper expounds the classification of high-strength bolts,analyzes the stress and deformation mechanism of friction type high-strength bolts of mining dump truck,and analyzes the nonlinear theory of stress and deformation of cab and bolts of mining dump truck based on ROPS.3.The minimum lateral loading,minimum lateral energy absorption and minimum longitudinal loading force of the ROPS structure of 200-ton mining dump truck are calculated and set according to the calibration standard and the research and development status of the truck.The lateral loading,lateral energy absorption and longitudinal loading simulation analysis were carried out on the ROPS structure of mining dump truck,and the related mechanical properties were analyzed,and the minimum lateral loading force required for subsequent analysis was obtained.Based on the minimum lateral load and minimum longitudinal load obtained,the theoretical forces of connecting bolts between cab and bottom frame under lateral and longitudinal loading of mining dump truck on horizontal road surface were analyzed.The theoretical force of bearing connection bolt of mining dump truck under the limit,downhill and limit side slope conditions is analyzed.4.Using the finite element analysis software ANSYS Workbench,the minimum lateral load and minimum longitudinal load simulation mechanical analysis were carried out on the cab of mining dump truck,and then the influence of the bolted connection mechanism between cab and chassis on the mechanical properties of the ROPS mechanism was analyzed.The simulation results of bolt stress analysis are compared with the theoretical analysis values mentioned above to verify the rationality of the simulation analysis,and according to the analysis results,the research basis for the subsequent bolt selection optimization is provided.In addition,through the analysis of the two welding connection schemes under the conditions of minimum lateral energy absorption and minimum longitudinal load,it can be seen that in the simulation analysis of welding connection,the error rates of the ROPS lateral and longitudinal displacement of the solid model with weld and the solid model without weld are within 5%,so the simulation of welding connection can use the solid without weld to save computing resources.5.In view of the optimization problem of bolt selection obtained from the above analysis,based on the original bolt type M30,the forces of M27 and M24 bolts in the model were calculated and analyzed theoretically.The optimal bolt type was selected,and the mechanical analysis was verified by simulation under lateral and longitudinal loading conditions.Through theoretical and simulation analysis,the rationality of bolt selection was verified.Finally,through the modal analysis of the bolt,analyze its natural frequency,and compare it with the operating frequency of the dump truck,verify the reliability of the bolt.